Recent progress towards understanding the synaptic ribbon.

Neurons of the visual, auditory and vestibular systems that signal through graded changes in membrane potential rely upon synaptic ribbons for the exquisite control of neurotransmitter release. Although clearly important for tonic neurotransmission, the precise role of synaptic ribbons remains elusive. In recent years, several genetic, biochemical, electrophysiological and optical approaches have begun to shed light on the functions of these enigmatic organelles.